The present invention relates to a common mode choke coil, and particularly to a common mode choke coil not susceptible to the effects of external noise.
Various structures have been proposed for common mode choke coils. One such common mode choke coil proposed in Japanese unexamined patent application publication No. 2003-217932 has two spiral coil elements disposed adjacent to each other but separated by an insulating layer. The two coil elements can be magnetically coupled.